Electrical equipment for material flow coordination between a plurality of conveyors, which are mechanically connected to one another, for conveying piece goods

ABSTRACT

The electrical equipment of mechanical conveyors and the associated material flow coordination between them, when a plurality of conveyors for conveying piece goods is connected, are provided. Intelligent motor starters are included, which are associated with the individual conveyors and respectively combine an autonomous totality composed of logic modules, and which are programmable with the functions required for material flow coordination, corresponding to the characteristics of the conveyor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority of German application No. 10 2008 013372.8 DE filed Mar. 10, 2008, which is incorporated by reference hereinin its entirety.

FIELD OF INVENTION

The present invention relates to the electrical equipment of mechanicalconveyors and to the material flow coordination between them associatedwith this, when a plurality of conveyors are connected.

BACKGROUND OF INVENTION

In a general form, the expression conveyors covers logically controlledconveyor techniques, such as roller conveyors, conveyor belts and chainconveyors for conveying piece goods.

In logistics, piece goods are transported between goods inwards andgoods outwards inter alia on conveyors whose aim is to sort the piecegoods and/or to distribute them, and/or to place them in store, tocommission them or to supply them to workstations or machines forfurther processing. This relates in particular to piece goods fromdispatch logistics, such as cartons, containers and packets,irrespective of whether these are in the singular form or are in thebulk material flow. The conveyors used are in general electricallypowered and transport said piece goods by carrying them to thepredetermined destination.

Small and medium-size logistic solutions with low-level requirements inthe material flow for the conveyors have a restricted performancespectrum for good solutions, or, depending on the solution requirement,they suffer from high costs in the basic outlay, as well as costsresulting from individual configurations.

It is known for electrical microcontroller boards to be used on theconveyor. These carry out the function of operating the drives and thecoordinating the material flow between the two conveyors in apredecessor/successor relationship. In general, the microcontrollerboards are specific solutions from the conveyor manufacturer and aredesigned and built for this specific conveyor, that is to say they arenot readily interchangeable. Furthermore, the use of microcontrollerboards on extra-low-voltage drives (for example 24 V or 48 V) isrestricted, as, therefore, is the performance of the drives and the loadof the piece goods, as well.

The functionality of the known solution is provided by the controllerboard with an external bus coupling; extensions are, however, restrictedwithin the predetermined product functionality and are possible only bythe manufacturer, and extensions cannot be implemented by the customer.Although the basic complexity is low in this known solution, the systemis, however, inflexible.

Furthermore, conveyors are known which are controlled by programmablelogic controllers (PLC) which record the status of the conveyor andmonitor the transfer of piece goods. In this case, low-voltage drives(for example 400 V) are also used, in addition to extra-low voltagedrives. The power is supplied and signal connections made centrally orlocally (bus-oriented). The functionality is defined individually in thePLC, and extensions to the logistic installation always require softwarechanges in the PLC by the supplier or the customer. Because of theindividuality that is required in some cases, the basic complexity ishigh, in particular for small to medium logistic solutions withlow-level requirements for the material flow.

This solution also makes use of motor starters which are mounteddecentralized on the conveyor or on the electrical drive. Depending onthe functionality, these are completely controlled by central logic orhave the capability to carry out the status monitoring for the drive, inorder to reduce the load on the central logic. However, they do not havethe capability to coordinate the material flow between two conveyorswithout superordinate logic with bus networking, for example control bya PLC.

SUMMARY OF INVENTION

The invention is based on the object of providing an intelligent,cost-effective and highly reliable system for driving a plurality ofconveyors which are connected to one another, which system makes itpossible, with little complexity, to connect the mechanical andelectrical parts of the conveyors to one another on a modular basis, andto extend or to change them when necessary.

In order to achieve the object, a system is proposed having the featuresdescribed in the independent claims, and refinements of the inventionare specified in the dependent claims.

The intelligent motor starters which are connected to one another areindependent of superordinate programmable logic controllers,microcontrollers, bus systems etc. The conveyors which are equipped withthe motor starters according to the invention can be operated on astand-alone basis and they are able, by interchanging signals with oneanother, to coordinate digital inputs and outputs of predecessor andsuccessor relationships between two conveyors, in order to transferpiece goods.

The logic modules that are created are programmed with the requiredfunctions, and each module is considered with defined characteristics,based on the characteristics of the conveyor. The invention thereforecreates an autonomous totality composed of the logic modules. Theelements required for voltage supply, switching devices, control andstatus-indication elements and interfaces are preferably combined in aswitch box to form the intelligent motor starter, which is considered tobe a technical product with defined characteristics.

The use of standard industrial components in the intelligent motorstarter developed from this results in independence from themanufacturer of the conveyor, and from the manufacturer's version of theconveyor. Furthermore, the standard industrial components have highreliability, which is generally subject to control by standards andcertification by independent test organizations. Different conveyorswith extra-low voltage or low-voltage drives can be connected to oneanother using the system according to the invention without any need forindividual adaptations (for example in a programmable logic controller)to software and hardware.

The functionality is stored and written in the logic modules. Thedifferent characteristics of the conveyors can be taken into account bydifferent intelligent motor starters. Standard interfaces between themotor starters allow mutual configuration to form a logistic solution,which is standard overall, with the individual conveyors. There is noneed for any superordinate logic in this case. All the required controland status elements can be provided on the motor starter.

Extensions and changes within the logistic solution can be achieved byconnection of the intelligent motor starter and of the conveyor to beadded. There is no need for programming knowledge for this purpose,since the elements are configured and connected. This considerablyreduces the effort required to set up an installation composed ofconveyors. In many cases, in particular for small to medium-sizedlogistic solutions, the functionality in the product spectrum of theintelligent motor starters is adequate.

Cost and quality advantages can therefore be expected by project-neutralmanufacturing configuration in large quantities; project implementationtimes and delivery times are thus reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The single figure in the drawing illustrates, highly schematically, fourconveyors 1 to 4 which belong to a conveyor installation and, accordingto the invention, are each linked to an intelligent motor starter M1-M4.

DETAILED DESCRIPTION OF INVENTION

The motor starters M1 to M4 are supplied with the required power by apower bus 5. According to the invention, each motor starter can beoperated on a stand-alone basis, although, as in the illustratedexample, it can be linked via digital inputs and outputs E and A toadjacent motor starters M1 to M4, with the motor starters M1 to M4 beingprogrammed with the required functions. As illustrated, motor starterswith direct drive functionalities M1, M2 and M4 can be connected via thestandard interfaces of the digital inputs and outputs E and A to theappropriately programmed motor starter M3 for a reversing drive.

The motor starters M1 to M4 are each arranged in a switch box 6, whichcontains the necessary elements for the voltage supply for the motors 7and for their control, the switching devices and the interfaces, andwhich, as can be seen, is fitted with the control and status-indicationelements 8.

1. Electrical equipment for material flow comprising: a plurality ofseparate conveyors, each mechanically connectable, one to another,without need for any individual hardware or software adaptations, theconveyors connected for conveying piece goods; and a plurality ofintelligent motor starters connected to one another, each of the motorstarters associated with an individual conveyor, the combined pluralityproviding a conveyor system operable in an autonomous manner,independent of and without any super ordinate controller or bus systemwhile, in the absence of both any such super ordinate controller and anysuch bus system, piece goods are transferred between two of theconveyors in the conveyor system based on an interchange of signals withone another, wherein the intelligent motor starters function as logicmodules, each user programmable to effect material flow coordinationbetween a pair of the connected conveyors.
 2. The electrical equipmentas claimed in claim 1, wherein a standard interface between theplurality of intelligent motor starters for mutual configuration formsan overall standard logistic solution for the conveyors.
 3. Theelectrical equipment of claim 2, wherein a predecessor and a successorrelationship is coordinated between a pair of conveyors via exchange ofa plurality of digital inputs and a plurality of outputs between theintelligent motor starters in the pair in order to transfer piece goodsbetween the pair of conveyors.
 4. The electrical equipment of claim 1further including a plurality of switch boxes, wherein (i) eachintelligent motor starter is positioned in one of the switch boxes and(ii) each combination of a motor starter in a switch box provides avoltage supply for a motor and control of the motor.
 5. The electricalequipment of claim 4, wherein the switch boxes comprise: elements forproviding a voltage supply, a plurality of switching devices, aplurality of control elements; a plurality of status-indicationelements; and interfaces.
 6. The electrical equipment of claim 4,wherein a plurality of different conveyor functionalities are storedamong different ones of the intelligent motor starters.
 7. Theelectrical equipment of claim 2, wherein a plurality of extensions and aplurality of changes within the logistic solution are made by connectionof a plurality of intelligent motor starters to a plurality ofconveyors.
 8. The electrical equipment of claim 1, wherein each motorstarter can be linked to adjacent motor starters for said interchange ofsignals with one another and can also be operated independently of theadjacent motor starters on a stand-alone basis.
 9. The electricalequipment of claim 1, wherein the intelligent motor starters havedifferent functionalities, the respective functionality of the motorstarters being written and stored in the programmable logic modulerespectively associated with the motor starters.
 10. The electricalequipment of claim 9, wherein the different functionalities are inrelation to different characteristics of the conveyors associated withthe intelligent motor starters.
 11. The electrical equipment of claim 1,wherein at least one motor starter can be programmed for a reversingdrive.